1. Field of the Invention
The present invention relates to a recording medium suitable for ink-jet recording.
2. Related Background Art
The ink-jet recording system conducts recording by ejecting ink droplets by a variety of ink ejection methods utilizing electrostatic suction, mechanical vibration or alternation of ink caused by a piezo element, bubbling of ink caused by heating, or the like method to deposit entire or a part of the ejected ink onto a recording medium such as a paper sheet, and a plastic film having an ink-receiving layer thereon. The ink-jet recording system is attracting attention owing to less noise generation, high speed of printing, and suitability for multi-color printing. The ink-jet recording systems are developed and are coming to be used widely as printers, copying machines, word processors, facsimile machines, plotters, and other information machines.
In recent years, digital cameras, digital videos, and scanners of high performance are supplied at low prices. With the wide use of personal computers, there increase chances of outputting the images of the above imaging instruments by the ink-jet system. Therefore, the ink-jet printing quality is required to be comparable with the quality of multi-color printing by silver salt type photograph or by a gravure system.
To meet the requirement, various improvements of ink-jet recording apparatuses and recording systems have been made, such as increase of the recording speed, increase of print fineness, improvement of full color printing quality, and so forth. On the other hand, the recording medium therefor is also required to have higher performance. The recording medium is also required to be capable of giving printed matters having gloss and high weatherability.
Various techniques have been disclosed therefor. For example, Japanese Patent Application Laid-Open No. 59-22683 discloses a highly ink-absorbent glossy printing sheet produced by coating with a two or more kinds of thermoplastic resin particles having different minimum film forming temperatures on a base material sheet face, and drying to form a film having cracks on the surface.
Japanese Patent Application Laid-Open Nos. 59-222381, 6-55870, 7-237348, and 8-2090 disclose methods for improvement of water resistance and weatherability of the printed image by use of a recording medium produced by forming a layer constituted of water-dispersible resin particles on the pigment layer surface, drying the layer at a temperature not higher than the glass transition temperature (Tg) of a thermoplastic resin particles to prepare a recording medium, and transforming the surface layer into a surface film after printing.
Japanese Patent Application Laid-Open No. 08-099457 discloses a recording medium having a layer containing an aqueous resin particles dispersed in a continuous surface film of a binder for improvement of ink fixability.
Japanese Patent Application Laid-Open No. 62-280067 discloses a recording medium having a melting temperature of not lower than 50xc2x0 C. Japanese Patent Application Laid-Open No. 62-1.40878 discloses a recording medium having a layer mainly composed of a particulate resin and a binder. Japanese Patent Application Laid-Open No. 62-271785 discloses a recording medium having a layer mainly constituted of a non-dyeable particle and a binder. Japanese Patent Application Laid-Open No. 62-140879 describes a recording medium having a layer having thermal adhesiveness/pressure adhesiveness.
However, the printing sheet disclosed in Japanese Patent Application Laid-Open No. 59-22683 does not have sufficient abrasion resistance owing to the fine cracks formed on the surface. The recording mediums disclosed in Japanese Patent Application Laid-Open No. 59-222381 and so forth are not sufficient in adhesiveness between the base material and particles owing to the heat treatment at a temperature lower than Tg, and are liable to be scratched owing to low abrasion resistance of the surface layer containing water-dispersible resin particles, and not steadily forming a uniform surface film on heating for transparency after printing, not giving high-quality images steadily, disadvantageously. The recording medium disclosed in Japanese Patent Application Laid-Open No. 08-099457, which has high abrasion resistance owing to the aqueous resin particles retained in the continuous binder surface film, is not suitable for the recent high-speed printing with the disclosed ink absorbency.
The recording mediums disclosed in Japanese Patent Application Laid-Open Nos. 62-280067, 62-140878, 62-271785, 62-140879, and so forth are not satisfactory in abrasion resistance of the recording face, sharpness of the image, and photographic image quality of high surface gloss which are required in recent years.
The object of the present invention is to provide a recording medium which offsets the above disadvantages of conventional recording mediums and has sufficient ink absorbency and high abrasion resistance.
The above object can be achieved by the present invention described below.
The recording medium of the present invention has, on a base material, a porous resin layer containing water-dispersible resin particles B having a minimum film-forming temperature of not lower than 0xc2x0 C., and water-dispersible resin particles A having a minimum film-forming temperature higher than that of the water-dispersible resin particles B and having an average particle size larger than that of the water-dispersible resin particles B.